Git is a versioning software. It keeps tracks of differents version and it allows software engineers to work in parallel with the safety that they won't ovewrite each other. Think about it like the Google Docs for programming.
Cloud vs Local copies
Allows programmers to update the same line of code and not ovewrite each other
Multiple copies of the same file
Can see changes in real-time
Single copy of file
Create a local copy of a repository
Sync your local version with the hosted version